/*
 *  JsonRpc-Cpp - JSON-RPC implementation.
 *  Copyright (C) 2008-2011 Sebastien Vincent <sebastien.vincent@cppextrem.com>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * \file netstring.cpp
 * \brief NetString implementation (http://cr.yp.to/proto/netstrings.txt).
 * \author Sebastien Vincent
 */

#include "netstring.h"

#include <cstdio>

#include <iostream>
#include <stdexcept>

namespace netstring
{
std::string encode(const std::string& str)
{
	unsigned long len = str.length();
	char strLen[32];
	std::string ret;

	/* format of a netstring is [len]:[string], */
	sprintf(strLen, "%lu:", len);
	ret.append(strLen);
	ret.append(str);
	ret.append(",");

	return ret;
}

std::string decode(const std::string& str) throw (netstring::NetstringException)
{
	unsigned long len = 0;
	size_t index = 0; /* position of ":" */
	size_t index2 = 0; /* position of "," */
	size_t i = 0;
	const char* data = str.data();
	std::string ret;

	index = str.find_first_of(":");
	if (index == std::string::npos)
	{
		/* error */
		throw NetstringException("netstring: missing ':' character");
	}

	index2 = str.find_last_of(",");
	if (index2 == std::string::npos)
	{
		/* error */
		throw NetstringException("netstring: missing ',' character");
	}

	for (i = 0; i < index; i++)
	{
		if (isdigit(data[i]))
		{
			len = len * 10 + (data[i] - (char) 0x30);
		}
		else
		{
			/* error */
			throw NetstringException("netstring: parsing error");
		}
	}

	if (len != (str.length() - index - 2))
	{
		/* error */
		throw NetstringException("netstring: size mismatch");
	}

	ret.assign(str, index + 1, len);
	return ret;
}

NetstringException::NetstringException(const std::string& msg) throw ()
{
	m_msg = msg;
}

NetstringException::~NetstringException() throw ()
{
}

const char* NetstringException::what() const throw ()
{
	return m_msg.c_str();
}
} /* namespace netstring */

